Engine designers have long been concerned about the separation of oil from an air flow in an engine ventilation system. Under certain operating conditions of the engine such as wide open throttle operation and/or operation under a relatively heavy load, for example, an outward flow of air passes from and engine crankcase, through the ventilation system, and into the air/fuel induction system. Other times, the air flow is in an opposite inward direction from the air/fuel induction system, through the ventilation system, and into the engine interior or crankcase.
Previously, engines have attempted to prevent the escape of significant quantities of oil with the above described outward air flow. Current engines utilize a baffle or multiple baffles within the valve cover of an engine and adjacent the air flow opening of the engine ventilation system. Disadvantages of such an arrangement are: the complexity and resultant cost; and the need to take-up valuable space within the valve cover which can result in increased engine size.
A pre-examination patent search of the subject oil separator uncovered the following U.S. Pat. Nos.: 5,205,848 to Blanc; 4,886,019 to Davis; 4,667,647 to Ohtaka; 4,515,137 to Manolis; 3,073,293 to Barker. The device disclosed in the Ohtaka patent is representative of the prior art separator using baffles formed in a valve cover. The device disclosed in the Davis patent provides a check valve to prohibit flow in both directions and does not provide an air/oil separator structure. The device disclosed in the Barker patent provides an oil separator structure using offset flow tubes or channels contained within a relatively voluminous housing. The device disclosed in the Manolis patent provides an oil separator structure using aligned flow tubs in combination with baffles. The device disclosed in the Blanc patent provides an oil separator structure in the form of a filter cartridge.